Items of electrical equipment housed within electronic component cases and within electrical junction boxes are commonly are served by pluralities of electrically conductive cables which communicate electrical power and electronic signals to and from the electronic equipment. In many cases, it is mechanically unacceptable to extend such electrically conductive cables through a bare or unprotected port within a wall of such case or box, such bare cable passages undesirably tending to wear against and damage the electrically conductive cables. Such unprotected cable extensions also tend to insecurely support the cables, and may undesirably allow stray electromagnetic radiation to enter the box or case. Accordingly, fasteners or couplers in the form of electrical connector backshell adaptors are commonly provided for protecting the passage of such electrically conductive cables into and out of an electrical component or junction box. Such adaptors commonly further function for securely mounting and terminating a protective cable sheath which may extend over the outward extension of the electrically conductive cable.
Electrically conductive cables extending to or from such electronic component or junction boxes are commonly grouped in substantially cylindrical bundles, such bundles having widely varying outside diameters. As a result of the wide variance of outside diameters of cable bundles which may extend to and from such cases or boxes, electrical connector backshell adaptors are commonly specially fitted and sized to include a cable receiving nipple component having a particularly sized bore or inside diameter. Requirements for close fitting of nipple inside diameters undesirably require a manufacturer or supplier of electrical connector backshell adaptors to design and maintain in large inventory including a multiplicity of differently sized adaptors, each being specially sized for accommodating a particular cable bundle diameter. Such sizing practice is wasteful, and leads to difficulties to matching an inventory of electrical connector backshell adaptors with a purchasing demand which varies in accordance with varying cable bundle sizes used by the backshell adaptor purchasers and users.
Another drawback or deficiency associated with use of such commonly known electrical connector backshell adaptors relates to stray electro-magnetic radiation. Upon extension of a cable bundle through the hollow bore of the nipple of a common electrical connector backshell adapter, a hollow annulus is typically formed between the inner wall of the backshell adaptor's nipple and the underlying annular outer surface of the cable bundle. While the outward extensions of such cable bundles are commonly sheathed by a flexible wire braid tube for reduction of stray currents within the cable bundle induced by outside electromagnet radiation, some amount of undesirable electromagnetic radiation may, in any event, travel within such cable sheaths, such EMR either entering from the outside through the sheath or being generated by the cables themselves or by interconnected electronic equipment. Such internal electromagnetic radiation may undesirably travel along the cable bundle and may undesirably enter an electronic component case through the annulus which typically overlies the cable bundle and underlies the inside inner wall of the backshell adaptor's nipple.
The instant inventive electrical connector backshell adaptor solves or ameliorates the above described problems, defects, and deficiencies by specially configuring a backshell adaptor nipple to hold and deploy a constant force spring (i.e., a Hunter or Negator spring), such adaptation utilizing such constant force spring to perform an annulus packing function within the nipple.